A subject-information acquiring apparatus includes a light source (108) a bed (102) supporting a subject (100) and having a holder (103) that holds an examined portion (101) of the subject acoustic wave detectors (104) configured to detect acoustic waves and output electric signals, the acoustic waves being generated when the examined portion is irradiated with light from the light source a supporting member (105) supporting the acoustic wave detectors such that a direction of maximum reception sensitivity of at least some acoustic wave detectors and a direction of maximum reception sensitivity of other acoustic wave detectors different from the at least some acoustic wave detectors differ and are directed toward a specific region and a signal processing unit (113, 613, 713) acquiring information about the inside of the examined portion based on the electric signals. The holder can be changed in shape to fit a shape of the examined portion.
